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arXiv · 2502.19375

Extracting scattering amplitudes for arbitrary two-particle systems with one-particle left-hand cuts via lattice QCD

André Baião Raposo·Raúl A Briceño·Maxwell T Hansen·Andrew W Jackura
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Abstract

We derive a general formalism that relates the spectrum of two-particle systems in a finite volume to physical scattering amplitudes, taking into account the presence of any left-hand branch cuts due to single-particle exchanges. The method first relates the finite-volume spectrum to an infinite-volume short-range quantity, denoted \mathcal{M}_0, and then relates the latter to the physical scattering amplitudes via known integral equations. The derivation of both relations is performed using all-orders perturbation theory and is exact up to neglected exponentially suppressed volume dependence. The relations hold for arbitrary two-particle systems with any number of coupled channels, non-identical and non-degenerate particles, and any intrinsic spin.

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André Baião Raposo, Raúl A Briceño, Maxwell T Hansen, Andrew W Jackura. 2025-02-26. Extracting scattering amplitudes for arbitrary two-particle systems with one-particle left-hand cuts via lattice QCD. https://arxiv.org/abs/2502.19375

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